Water-repellent packing material



C. GOTTWALD WATER REPELLENT PACKING MATERIAL April 21, 1931.

Filed Aug. 12, 1927 33221672 for:

Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE CHRISTIAN GOTT'WALD, OF CLEVELAND, OHTO, ASSIGNOR TO THE RIG-WIL GOM PAJNY, OI

CLEVELAND, OHIO, A. CORPORATION OF OHIO wA'I'ER-REPELLENT rncxme MATERIAL Application filed August 1?,1927. Serial No. 212,502.

- The present invention relates to an improvement in underground conduit systems, in which a pipe or pipes for conveymg a liquid or gas are housed within'an envelo ingstructure of metal, tile, concrete or bric The invention has particularly to do with i the matter of packing for surrounding the pipe or pipes within the housing or envelope, the packing having the peculiar property of 2 1o repelling water, so that the same will not beof conduit, usually made of. Vitreous ma-' terial. A well known form of base drain is indicated at 2.

Within the conduit is a pipe 4 for fluid conducting purposes, which pipe is supported upon supports 5 which are of a well known commercial form.

Surrounding the pipe and confined within the conduit is the thermo non-conducting packing material to which reference is made later on in this specification.

Underground conduit systems are prone to have moisture accumulate within the outer casing or conduit, either because of moisture condensing, or in some instances from the ingress of water from the outside.

It is usual in underground conduit systems to provide some sort of draining feature, both to drain water from the surrounding earth in which the conduit is placed, and.

also to provide suitable vents or means by which water that may accumulate or find its we? into the conduit itself may be drained.

n underground conduit systems where the pipe or pipes are conveying a liquid or gas which is either above or below the normal temperature, as for instance steam, or on the other hand a refrigerant as or fluid, it is necessary to enclose and pac the pipe orpipes Russuu) with some suitable non-conductor of heat. The difiiculty has been that the usual'fforms of thermo non-conductors become impregnated with water or moisture, and thus decrease, and with the accumulation of suflicient moisture break down the thermo non-conductivit of the packing. The usual packings whic have heretofore been employed, such as shredded asbestos, rock wool and mineral 'wool are in each instance comprised of siliceous fibers which of themselves are waterproof. These substances being crystalline in structure and not cellular will not absorb water, so that they may be properly described as water-proof. However, when these substances are used as packing materials in undeground conduit systems, the water which condenses within the conduit or finds its way into the conduit from outside sources will nevertheless soak the fibrous mass, the water finding its way into the interstices between the fibers and there bein held, and upon a sufiicient accumulation 0% water the thermo non-conductivity of the packing mass is impaired or destroyed. Apparently the water penetrates into the mass of fibers by capillarity and lodges in the interstices between the fibers, and this will occur even though care is taken-to sufficiently pack the fibrous mass so as to avoid leakage or appreciable pockets in the packing.

The present invention has to do with a packing material, which, by treatment, is rendered water repellent, and by this is meant that water coming in contact with a mass of fibers is repelled,- so that the water does not find its way into the interstices between the fibers.

More specifically speaking a fibrous packing material, such as shredded asbestos, rock wool, mineral wool orequivalent material which in usual commercial form is unmatted packin water coming in contact with the mass 0 fibrous material will be repelled and the water will run down the inner'wall of the envelopin conduit to be discharged through the usual Ease drain; The efiect of the treatment given to the fibers of the fibrous material seems to be in effect to break down the usual capillary action, by which water mi ht ordinarily be drawn into the interstices etween the fibers, and b virtue thereof the water is repelled. Whet er the foregoing be the correct explanation of the phenomena is not important, but the fact that the fibers are rendered repellent to water is important.

The fibrous material may be treated, to render it water repellent, by various substances, one of which may be mentioned being a five to ten percent solution of aluminum stearate, this specific substance bein not included in the present invention but orming the subject matter of a copending application, filed in the name of Carl A. Black, Serial No. 212,604, filed August 12, 1927 I am aware that it has been heretofore proposed to treat certain material which is cellular in nature in order to make it water-proof, but my invention differs from such procedure in that it makes the fibrous material treated water repellent.

Merely being water-proof is not suflicient, for, as before pointed out, asbestos, rock wool and mineral wool are all inherently waterproof, but nevertheless a fibrous mass of these materials will watersoak by the accumulation of water in the interstices between the fibers.

It is only by making the fibers water repellent so that water will not accumulate in the interstices between the fibers, that an eflicient packing for underground pipes which are housed in conduits can be obtained.

Having thus described my invention what I claim as new is:

1. The combination with a conduit having drainage means and a fluid conducting pipe therein, of a mass of thermo-non-conducting material comprising a mass of unmatted and comparatively loosely associated mineral fibers coated with material which renders them water repellent, surrounding said pipe and within the conduit.

2. The combination with a conduit having drainage means and a fluid conducting pipe therein, of a mass of thermo-non-conducting material comprising a mass of unmatted comparatively loosely associated asbestos fibers coated to render them water repellent surrounding said pipe and within the conduit.

In testimony whereof, I hereunto afiix my signature.

CHRISTIAN GOTTWALD. 

